A linear guide device or curved guide device is provided with a guide rail, a slider constituted by a slider body and end caps fastened at the two end parts in the movement direction, and a plurality of rolling elements. The guide rail and slider have rolling surfaces arranged to face each other and constitute a rolling passage of the rolling elements. The slider further has a return passage of rolling elements and a direction changing path which communicate the return passage and the rolling passage. Further, the rolling passage, the return passage, and the direction changing path constitute a circulation path of the rolling elements. By the rolling elements being circulated through the circulation path, one of the guide rail and the slider moves relative to the other in the rail direction. FIG. 10 is a perspective view which shows an example of a curved guide device. As shown in FIG. 10, the curved guide device has an endless guide rail 1 and a slider 2.
When assembling rolling elements in the circulation path of such a guide device, in a guide device with no holder which holds the rolling elements, first the following is performed. In the case of a linear guide device, one end cap is attached to one end part of the slider body in the movement direction, then this is made to slide and move from the end part of the guide rail to place the two leg parts of the slider body and end cap guide at the two sides of the rail in the width direction. In the case of a curved guide device, the slider body is placed over the guide rail to arrange the two leg parts of the slider body at the two sides of the guide rail in the width direction, then split members of an end cap, split into left and right parts, are attached to one end part of the slider body in the movement direction from the outside and inside of the guide rail.
Next, rolling elements are inserted from the other end of the slider body in the movement direction at which no end cap is attached to the rolling passage, return passage, and direction changing path of the end cap attached to the slider body. Next, rolling elements are inserted into the direction changing path of the other end cap and this end cap is fastened to the other end part of the slider body in the movement direction.
As a guide device, there is a preloaded device to which a preload is applied to improve the rigidity. In the case of such a preloaded device, unless a pressing force is exerted, the rolling elements in the rolling passage cannot move. It takes time particularly for the work of assembling the rolling elements.
Patent Document 1 describes a curved guide device having an endless guide rail. The slider body (casing) is formed with rolling element insertion holes (assembly holes) for inserting rolling elements to the circulation path. The rolling element insertion holes communicate with the return passages and open to the outside and that after inserting the rolling elements, the holes are then sealed by plugs.
In the specific example of Patent Document 1, the opened shapes of the rolling element insertion holes are circular. The holes open at the two side surfaces of the slider body in the width direction. Plugs are inserted into these insertion holes, and then the plugs are fastened to the slider body by fastening pins inserted from the top surface of the slider body (member mounting surface). Besides, Patent Document 1 does not describe the method of insertion of the rolling elements.
Patent Document 2 describes assembling balls into a curved guide device (slewing bearing) by cutting away parts of the two side surfaces of the slider body (bearing body) so as to include the outside halves of the grooves of the return passages and constitute lids, removing the lids and inserting balls from the return passages to the circulation path, and attaching the lids to prevent the balls from escaping. In this method, however, since the parts of the lids are large, it is necessary to increase the dimension of the slider body in the width direction so as to secure rigidity of the slider body. In addition, since the return passages are split at the lid parts, the structure becomes complicated and a high precision is needed for the working and assembling.